Complete the equation. $\dfrac{2}{5}+ \dfrac{2}{5} + \dfrac{2}{5} + \dfrac{2}{5}~=$
Answer: Let's figure out what $\dfrac{2}{5}+ \dfrac{2}{5} + \dfrac{2}{5} + \dfrac{2}{5}$ equals. $1$ $\dfrac{0}{5}$ $\dfrac{2}{5}$ $\dfrac{4}{5}$ $\dfrac{6}{5}$ $\dfrac{8}{5}$ $\llap{{+}}\!\frac{2}{5}$ $\llap{{+}}\!\frac{2}{5}$ $\llap{{+}}\!\frac{2}{5}$ $\llap{{+}}\!\frac{2}{5}$ $\dfrac{2}{5}+ \dfrac{2}{5} + \dfrac{2}{5} + \dfrac{2}{5}= \dfrac{8}{5}$ Now, let's figure out how many times we add $\dfrac{1}{5}$ to make $\dfrac{8}{5}$. $\dfrac{0}{5}$ $\dfrac{1}{5}$ $\dfrac{2}{5}$ $\dfrac{3}{5}$ $\dfrac{4}{5}$ $\dfrac{5}{5}$ $\dfrac{6}{5}$ $\dfrac{7}{5}$ $\dfrac{8}{5}$ $\llap{{+}}\!\frac{1}{5}$ $\llap{{+}}\!\frac{1}{5}$ $\llap{{+}}\!\frac{1}{5}$ $\llap{{+}}\!\frac{1}{5}$ $\llap{{+}}\!\frac{1}{5}$ $\llap{{+}}\!\frac{1}{5}$ $\llap{{+}}\!\frac{1}{5}$ $\llap{{+}}\!\frac{1}{5}$ $=\overbrace{{\dfrac1{5}} +{\dfrac1{5}} +{\dfrac1{5}} + {\dfrac1{5}} + {\dfrac1{5}} + {\dfrac1{5}} + {\dfrac1{5}} + {\dfrac1{5}}}^{{8}\text{ fifths}} $ $=\dfrac{{8}\times{1}}{{5}}$ $\dfrac{2}{5}+ \dfrac{2}{5} + \dfrac{2}{5} + \dfrac{2}{5} = 8 \times \dfrac15$